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Finding the Fourth Proportional to 518.25, 780.94 and 428.95

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Solution

The fourth proportional to 518.25, 780.94 and 428.95 is: 646.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.25 : 780.94 = 428.95 : x
  2. Step 2: Convert to fraction form
    518.25/780.94 = 428.95/x
  3. Step 3: Cross multiply
    518.25x = 780.94 × 428.95
  4. Step 4: Simplify right side
    518.25x = 334,984.21
  5. Step 5: Solve for x
    x = 334,984.21/518.25
  6. Step 6: Final answer
    x = 646.38

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.